Francis Rainsford

Background

The fact that Arequipa has between seven and ten hours of sunshine for 365 days of the year was the basic tenet and inspiration for a project to use solar energy in at least one of the manufacturing processes in the city?s alpaca knitting industry, namely final garment pressing.

In 2013, local textile consultant, Roberto Lopez, approached the Technical Engineering Institute, Tecsup, and alpaca knitting company, Textiles Allpaka S.R.L., with a proposition to design and build a device to harness the sun?s rays in this regard and the three parties agreed to work together.

Next, Lopez submitted a proposal for funding the project to Peru?s Ministry of Production?s Fondos para la Innovacion, Ciencia y Tecnologia (FINCyT) and received a favourable reply.

The team duly went to work developing the system and the prototype was installed and on-stream in June of this year.

Tecsup

Tecsup is a private educational organization founded by Luis Hochschild in Lima in 1984 with the aim of teaching engineering skills to school leavers and apprentices from industry.

Equipped with state-of the-art machinery, a curriculum is based on programmes established in the German educational system, its Arequipa locale was set-up in 1993.

Aside from its courses for students, the organization carries out research and development projects for industry and was instrumental in designing and constructing the cylindrical collecting dish for the sun?s rays at the heart of this particular solar energy project.

Once the final design for the concave dish was agreed, the first practical challenge was to determine what metal could be used that was capable of withstanding long hours of intense temperatures from the sun. After various trials, a ?blend? of stainless steel and aluminium was found to be the best performer.

Next, a device to track the sun?s movement during the hours of the day needed to be engineered and this was eventually achieved with a timer programmed with the astrological movement pattern for the sun for any particular time of year.

This device is linked to a motor that gyrates the dish accordingly so that it always collects the rays at their most intense focus. In fact, this principle of concentrating the sun?s rays together in a small area actually increases the amount of energy that can be produced.

The solar energy provided by the dish is used to heat water in a boiler where the subsequent steam produced is channelled, under pressure, through a network of pipes and traps to the individual pressing irons.

Environmental and quality benefits

Arequipa, in line with many other industrial cities worldwide, suffers from poor quality air caused, in the main, by emissions from its vehicular traffic and its factories. Its dry, desert conditions exacerbate this pollution which, in turn, adversely affects the respiratory health of its inhabitants.

Traditional methods of generating energy employed in the city generally involve the use of standard boilers fuelled by oil or diesel which result in toxic contaminants being released into the atmosphere. Employing solar energy is a giant stride in reducing this type of pollution and improving the quality of people?s lives.

One of the many properties associated with alpaca fibre is its ability to maintain its appearance in garment form. The fibre?s overall low and non-prominent scale count and resultant relatively smooth exterior surface helps to minimise pilling and felting tendencies which enable it to keep its ?brand new? look longer than garments made from other natural animal fibres, such as wool for example.

This valuable selling point can easily be squandered by poor quality and production control in the final pressing process. The main causes being:

1) Poor efficiency of standard steam boilers which are often questionable with occurrences of ?contaminated? steam staining textile garments during their final pressing, resulting in quality downgrades and loss of commercial income.

2) If using electric irons, the temperature often increases without control and where excessive heat deforms the alpaca fibres in the garment leaving shiny, unsightly patches on it.

3) Excessive temperatures that deform the fibres also affect the strength and recovery properties of the garment by exaggerating the fibre?s plasticity at the expense of its elasticity.

4) Pressing at too high a temperature can flatten the garment and diminish its voluminosity.

Lopez explained, ?Turning to the alternative of solar energy has had two immediate benefits. Firstly, the ?cleaner? quality of steam produced together with better control of the average temperature has improved the look and handle of finished garments - which, in this particular case, are destined for export markets where customer demands are much more stringent.?

?Secondly, the cost of energy has dropped dramatically, even when taking into account the capital outlay of the Tecsup equipment and its steam distribution system which is currently being evaluated by Tecsup for offering to the marketplace on a commercial basis. A cursory calculation of the raw materials and technology employed in its construction indicates that commercial units can be reproduced at a reasonable cost to interested parties - at least locally.?

Environmental benefits aside, the improvements in the final quality of garments achieved after pressing with this system has encouraged the International Alpaca Association to conduct its own investigation and tests as to how such advances might be incorporated into its own quality norms for alpaca fibre.

A model for a sustainable future for the alpaca industry with solar energy

The abundance of sunlight in Arequipa is too good a natural resource to waste in a world where the long-term forecast for fossil fuels is one of ever-increasing prices leading to a higher cost for electricity.

Environmental considerations are commanding more attention, too, as most analysts insist that future economic growth can only be achieved and sustained using green business strategies.

Commenting on both prognoses, Lopez concludes, ?Our solar energy project has been successful in enabling a medium-sized alpaca knitting company to improve its final garment quality and, at the same time, lower its energy costs. This has to be the way forward and, in this regard, I?m already looking to employ the same principles on a much bigger scale where solar energy can be used for the water heating needs of alpaca fibre scouring plants and dyehouses.?

?I have been in discussions with Tecsup as to how, together, we can surmount the challenges posed and strike another positive chord for Arequipa?s alpaca fibre processing industry?s future.?
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Photographs in ?jpeg? attachments:


Reference Description
Solar1 Roof-mounted Tecsup prototype cylindrical collecting dish
for the sun?s rays together with its automatic tracking
device.

Solar2 Operative using flat steam iron powered by solar energy.
One of the system?s steam traps can be seen mounted on the
wall on the left-hand side of the photo.

Solar3 Finished alpaca garments after pressing with flat steam irons
powered by solar energy.

Solar5 Roberto Lopez, independent textile consultant for the solar
energy pressing project.